Alaska - covering more square miles than Texas, California and Colorado put together - is home to some of Earth's most amazing natural features. Alaska hosts North America's highest peak and one of the coldest mountains on the globe; the biggest oil field on the continent; a volcano with the record for the 20th century's biggest eruption; a glacier so huge it would nearly cover the entire state of Rhode Island; and the most powerful earthquake ever to be recorded in North America.
Alaska is a relatively new land born of massive collisions and molten lava. Built from pieces of volcanic and continental rock and seafloor pushed into place by movements of the Earth's Pacific and North American plates, Alaska's landscape continues to change. Most of Alaska continues to grow; Denali, also known as Mount McKinley, has a rate of uplift of about 1 mm per year.
There are more than 40 active volcanoes in Alaska, and most are strung out in an approximately1500-mile long strand of islands called the Aleutian Arc. This chain of small islands separate the Bering Sea from the Pacific Ocean, and provide nesting habitat for nearly 40 million seabirds.
Alaska's glaciers have expanded and retreated for thousands of years during the Ice Ages. Today, they cover five percent of Alaska. An estimated 100,000 glaciers hold about three-fourths of Alaska's fresh water. These glaciers have carved out the landscape into spires, valleys and fjords.
As many as 4,000 earthquakes of various depths are recorded in Alaska every year--more than occur throughout the rest of the United States. The Pacific Plate, a huge slab of the Earth's outer rocky layer, moves down under the edge of the North American Plate. The on-going movement makes this area of Alaska one of the world's most active seismic areas.
Building Extreme Alaska is a tour of a construction zone that features Alaska's natural engineering marvels. Alaska is a land of extreme natural architecture and forces: active volcanoes, frequent earthquakes, harsh weather and climate, and glaciers in never ending motion. Still under construction, Alaska keeps growing and grinding, melting and shaking.